chased or embossed, it will be found that the hollow parts do not receive the deposit at all, or very partially. When this is the case, the article must be rinsed and well scratch brushed, and a little more cyanide added to the solution. The anode must be slightly kept in motion and the battery power increased until the hollow surfaces are coated. Frequent scratch brushing aids the deposit to a great extent by imparting a slight film of brass to the surface.
In gilding chains, brooches, pins, rings, and other articles which have been repaired, i.e, hard soldered, sometimes, it is found that the gold will not deposit freely upon the soldered parts; when such is the case, a little extra scratch brushing applied to the part will assist the operation greatly and it has some times been found that dry scratch brush ing for an instant that is, without the stream of beer usually employed renders the surface a better and more uniform conductor and consequently it will more readily receive the deposit. In fact, dry scratch brushing is very useful in many cases in which it is desirable to impart an artificial coating of brass upon an article to which silver or gold will not readily adhere. In scratch brushing without the employment of beer or some other liquid, however, great care must be taken not to continue the operation too long, as the minute particles of metal given off by the scratch brush would be likely to prove prejudicial to the health of the operator, were he to inhale them to any great extent.
The following solutions are for gilding without a battery:
I. In 1,000 parts of distilled water dissolve in the following order:
Crystalline sodium pyrophosphate 80 parts
Twelve per cent solution of hydrocyanic acid 8 parts
Crystalline gold chloride 2 parts
Heat to a boiling temperature, and dip the article, previously thoroughly cleaned, therein.
II. Dissolve in boiling distilled water, 1 part of chloride of gold and 4 parts of cyanide of potassium. Plunge the objects into this solution, while still hot, and leave them therein for several hours, keeping them attached to a copper wire or a very clean strip of zinc. They will become covered with a handsome gold coating.
I. Dissolve 6 parts of gold in aqua regia and dilute the solution with distilled water; on the other hand, put 30 parts of lime in 150 parts of distilled water; at the end of 2 hours add the gold solution to the lime, shake all and allow to settle for 5 to 6 hours, decant and wash the precipitate, which is lime aurate. Place this aurate of lime in 1,000 parts of distilled water, with 20 parts of hyposulphite of soda; put all on the fire for 8 to 10 minutes, without allowing to boil; remove and filter. The filtered liquor serves for gilding in the cold, by plunging into this bath the aluminum articles previously pickled by passing through caustic potash and nitric acid. This gilding is obtained without the aid of the battery.
II. The gold bath is prepared with gold dissolved in the usual way, and the addition of salts, as follows: Gold, 20 parts, by weight; sulphate of soda, 20 parts; phosphate of soda, 660 parts; cyanuret of potassium, 40 parts; water, 1,000 parts. The bath ought to be of the temperature of 68º to 77º F.
Amalgam Gold Plating. Gold amalgam is chiefly used as a plating for silver, copper, or brass. The article to be plated is washed over with diluted nitric acid or potash lye and prepared chalk, to remove any tarnish or rust that might prevent the amalgam from adhering. After having been polished perfectly bright, the amalgam is applied as evenly as possible, usually with a fine scratch brush. It is then set upon a grate over a charcoal fire, or placed into an oven and heated to that degree at which mercury exhales. The gold, when the mercury has evaporated, presents a dull yellow color. Cover it with a coating of pulverized niter and alum in equal parts, mixed to a paste with water, and heat again till it is melted, then plunge into water. Burnish up with a steel or bloodstone burnisher.
Brass Gilding. On brass, which is an electropositive metal, an electromagnetic metal, such as gold, can be deposited very cheaply from the dilute solutions of its salts. The deposit is naturally very thin, but still quite adhesive. In preparing it, the proportions stated be- low have to be accurately observed, otherwise no uniform, coherent coating will result, but one that is uneven and spotted.
I. In 750 parts, by weight, of water dissolve: Phosphate of soda, 5 parts, and caustic potash, 3 parts, and in 250 parts of water, gold chloride, 1 part, and potassium cyanide, 16 parts. Mix both
solutions well and cause the mixture to boil, whereupon the brass articles to be gilded are immersed. The gold in the mixture can be utilized almost entirely. When the solution does not gild well any more a little potassium cyanide is added, and it is used for pre-gilding the articles, which can then be gilded again in a fresh solution. This solution is very weak. A stronger one can be prepared mechanically by dissolving 2 to 3 parts of gold chloride in very little water to which 1 part of saltpeter is added. Into this solution dip linen rags, let them dry in a dark place, and cause them to char into tinder, which is rubbed up in a porcelain dish. Into the powder so made, dip a soft, slightly charred cork, moistened with a little vinegar, or else use only the finger, and rub the gold powder upon the brass articles.
II. To Give Brass a Golden Color, it is dipped until the desired shade is obtained into a solution of about 175º F., produced as follows: Boil 4 parts of caustic soda, 4 parts of milk sugar, and 100 parts of water for 15 minutes; next add 4 parts of blue vitriol, dissolved in as little water as possible.
Copper and Brass Gilding. The solutions used to gild copper can be generally used also for brass articles. Copper gilding acquires importance because in order to gild iron, steel, tin, and zinc, they must first be coated with copper, if the boiling method is to be employed. Following is Langbein's bath for copper and brass:
Dissolve 1 part, by weight, of chloride of gold and 16 parts, by weight, of potassium cyanide in 250 parts, by weight, of water; dissolve also and separately, 5 parts, by weight, of sodium phosphate and 3 parts, by weight, of caustic potash in 750 parts, by weight, of cold water. Mix these solutions and bring them to a boil. If the action subsides, add from 3 to 5 parts, by weight, more potassium cyanide. The polished iron and steel objects must first be copper-plated by dipping them into a solution of 5 parts, by weight, of blue vitriol and 2 parts, by weight, of sulphuric acid in 1,000 parts, by weight, of water. They may now be dipped into a hot solution containing 6 parts, by weight, of gold chloride and 22 1/2 parts, by weight, of soda crystals in 75 parts, by weight, of water. This coating of gold may be polished.
Cold Chemical Gilding. The chemical gilding by the wet process is accomplished by E. E. Stahl with the aid of three baths: A gold bath, a neutralization bath, and a reduction bath. The gold bath is prepared from pure hydrochloric acid, 200 parts; nitric acid, 100 parts; and pure gold. The gold solution evaporated to crystallization is made to contain 1 1/2 per cent of gold by diluting with water. The neutralization bath consists of soda lye of 6º, of pure sodium hydroxide, and distilled water. The reduction bath contains a mixture of equal parts of 90 per cent alcohol and distilled water, wherein pure hydrogen has been dissolved. The gilding proper is conducted by first entering the article in the gold bath, next briskly moving it about in the neutralization bath, and finally adding the reducing bath with further strong agitation of the liquid. The residues from the gilding are melted with 3 parts each of potash, powdered borax, and potash niter, thus recovering the superfluous gold. The gilding or silvering respectively produces a deposit of gold or silver of very slight thickness and of the luster of polishing gold. Besides the metal solution an "anti-reducer" is needed, consisting of 50 grams of rectified and rosinified turpentine oil and 10 grams of powdered roll sulphur. From this is obtained, by boiling, a syrupy balsam, to which is added, before use, lavender oil, well ground basic bismuth nitrate, and the solution for gilding or silvering. The last takes place by a hydrochloric solution of aluminum with the above balsam.
Colored Gilding. A variety of shades of green and red gold can be obtained by the electro-chemical process, which method may be employed for the decoration of various objects of art. In order to produce red gold in the different shades, a plate of pure copper is hung into a rather concentrated gold bath (5 to 6 parts, by weight, per 1,000 parts of liquid), which is connected with the battery in such a manner that gold is deposited on the article immersed in the bath. By the action of the electric current copper is dissolved as well from the copper plate and is separated simultaneously with the gold, so that, after a certain time, a deposit containing a gold copper alloy, conforming in color to the quantities of gold and copper contained in it, is obtained by the electric process. When the desired shade of color of the deposit is reached the copper plate is taken out and replaced by another consisting of the copper gold alloy, likewise produced by electrodeposition, and the articles are now gilt in this liquid. In some large manufactories of gold articles this last coloring is used even for pure
gold articles, to give them a popular color. To produce green gold (alloy of gold and silver), a silver plate is first employed, which is dipped into the gold bath and from which enough silver is dissolved until the separating alloy shows the desired shade. The silver plate is then exchanged for a gold-silver plate of the respective color, and the articles are gilt with green gold.
Gilding German Silver. In gilding German silver the solution may be worked at a low temperature, the solution being weakened and a small surface of anode exposed. German silver has the power of reducing gold from its solution in cyanide (especially if the solution be strong) without the aid of the battery; therefore, the solution should be weaker, in fact, so weak that the German silver will not deposit the gold per se; otherwise the deposit will take place so rapidly that the gold will peel off when being burnished or even scratch brushed.
Gilding of Glass.
I. In order to produce a good gilding on glass, the gold salt employed must be free from acid. Prepare three solutions, viz.:
a. 20 parts acid-free gold chloride in 150 parts of distilled water.
b. 5 parts dry sodium hydrate in 80 parts of distilled water.
c. 2 1/2 parts of starch sugar in 30 parts distilled water; spirit of wine, 20 parts; and commercial pure 40 per cent aldehyde, 20 parts. These liquids are quickly mixed together in the proportion of 200, 50, and 5 parts, whereupon the mixture is poured on the glass previously cleaned with soda solution, and the gilding will be effected in a short time. The gold coating is said to keep intact for years.
II. Coat the places to be gilded thinly with a saturated borax solution, lay the gold leaf on this and press down well and uniformly with cotton-wool. Heat the glass over a spirit flame, until the borax melts, and allow to cool off. If the glass is to be decorated with gilt letters or designs, paint the places to be gilded with waterglass solution of 40º Bé.; lay on the gold leaf, and press down uniformly. Then heat the object to 86º F., so that it dries a little, sketch the letters or figures on with a lead pencil, erase the superfluous gold, and allow the articles to dry completely at a higher temperature.
Green Gilding. This can be obtained conveniently by the galvanic process, by means of anodes of sheet platinum with the following composition: Water, 10,000 parts, by weight; sodium phosphate, 200 parts; sodium sulphate, 35 parts; potassium carbonate, 10 parts; 1 ducat gold from gold chloride, potassium cyanide (100 per cent), 20 parts. Dissolve the first three salts in 10,000 parts of cold water and add, with stirring, the gold chloride and potassium cyanide. Before the first use boil down the solution thoroughly about one half, replacing the evaporating water and filter after cooling, in case a sediment should appear. To this gold bath very carefully add some silver bath. The platinum sheets which are to serve as anodes are employed 1 3/4 inches long, 1/3 inch broad, and 1/100 of an inch thick. With these anodes the gold tone can be somewhat regulated by hanging more or less deeply into the solution during the gilding. The current should have a tension of 3 to 4 volts. In the case of batteries three Busen elements are connected for current tension. It is difficult to produce old gold on silver, especially if the raised portions are to appear green. It is most advantageous first to lightly copper the silver goods, taking the copper off again on the high places by brushing with pumice stone. After that hang at once in the above gold bath. If the embossed portions should be too mat, brighten slightly by scratching with a very fine brass wire brush. In this manner a handsome brown shade is obtained in the deep places and a green color on the raised portions. This process requires practice. Since this method will produce only a very light gilding, a coating of white varnish will protect the articles from tarnishing.
Incrusting with Gold. The article is first made perfectly bright, and those places which are to be gilt are covered with a matt consisting of white lead ground with gum water, made into a paste which can be applied like a thick paint by means of a pen or brush. Those places of the metal surface not covered by the paint are coated with asphalt varnish a solution of asphaltum in benzine to which oil of turpentine is added to render it less volatile. After this is done lay the article in water, so that the white lead paint comes off, and put it into a gilding bath. By the electric current gold is precipitated on the bright parts of the metal. When the layer of gold is thick enough lift the object from the bath, wash, let dry and lay it into a vessel filled with benzol. The asphalt dissolves in the benzol, and the
desired design appears in gold on the bronze or silver ground. This operation may also be performed by coating the whole article with asphalt varnish and executing the design by means of a blunt graver which only takes away the varnish covering without scratching the metal itself. On the parts thus bared gold is deposited by the electric current and the varnish coating is then removed.
I. The pattern is painted with a fine camel's hair pencil, moistened with gold chloride. Hold the ivory over the mouth of a bottle in which hydrogen gas is generated (by the action of dilute sulphuric acid on zinc waste). The hydrogen reduces the auric chloride in the painted places into metallic gold, and the gold film precipitated in this manner will quickly obtain a considerable luster. The gold film is very thin, but durable.
II. This is especially suitable for monograms. Take gold bronze and place as much as can be taken up with the point of a knife in a color cup, moistening with a few drops of genuine English gold paint. Coat the raised portions sparingly with gold, using a fine pencil; next, coat the outer and inner borders of the design. When the work is done, and if the staining and gilding have been unsuccessful, which occurs frequently at the outset, lay the work for 5 or 10 minutes in warmed lead water and brush off with pumice stone. By this process very fine shades are often obtained which cannot be produced by mere staining. Since the gold readily wears off on the high places of the work, it is well to lightly coat these portions with a thin shellac solution before gilding. This will cause the gilding to be more permanent.
Mat Gilding. To obtain a handsome mat gilding the article, after having been neatly polished, is passed through a sandblast, such as is found in glass grinding and etching establishments; next, the object is carefully cleansed of fine sand (if possible, by annealing and decocting), whereupon it is gilt and subsequently brushed mat with the brass brush. Where there is no sandblast, the article is deadened with the steel wire brush, which will produce a satisfactory result, after some practice. After that, treatment is as above. The above-mentioned applies in general only to silver articles. In case of articles of gold, brass, or tombac, it is better to previously silver them strongly, since they are too hard for direct treatment with the steel wire brush, and a really correct mat cannot be attained. The brushes referred to are, of course, circular brushes for the lathe.
Dead-Gilding of an Alloy of Copper and Zinc. The parts which are to be deadened must be isolated from those which are to be polished, and also from those which are to be concealed, and which therefore are not to be gilded. For this purpose they are coated with a paste made of Spanish white mixed with water. The articles prepared in this manner are then attached by means of iron wire to an iron rod and suspended in a furnace constructed for this process. The floor of this furnace is covered on four sides with plates of enameled earthenware for receiving the portions spattered about of the salt mixture given off later.
In the middle is an oven constructed like a cooking stove, on which is an iron tripod for carrying the deadening pan; this latter is cemented into a second pan of cast iron, the intervening space being filled up with stove cement. In the middle of the pan is the bottom or sill, provided with a thick cast iron plate, forming the hearth. On all four sides of the latter are low brick walls, connecting with the floor of the furnace, and the whole is covered with thick sheet metal. On the side of the furnace opposite the side arranged for carrying the pans, is a boiler in which boiling water is kept. On the same side of the furnace, but outside it, is a large oval tub of a capacity of about 700 or 800 quarts, which is kept filled with water. The upper portions of the staves of this tub are covered with linen to absorb all parts that are spattered about.
Powder for Gilding Metals.
I. In a solution of perchloride of gold soak small pieces of linen which are dried over the solution so that the drops falling therefrom are saved. When the rags are dry burn them, carefully gathering the ashes, which ashes, stirred with a little water, are used for gilding either with pumice stone or with a cork. For the hollows, use a small piece of soft wood, linden, or poplar.
II. Dissolve the pure gold or the leaf in nitro-muriatic acid and then precipitate it by a piece of copper or by a solution of iron sulphate. The precipitate, if by copper, must be digested with distilled vinegar and then washed by pouring water over it repeatedly and dried. This precipitate will be in the form of very fine powder; it works better and is
more easily burnished than gold leaf ground with honey.
I. A good gilding paste is prepared as follows: Slowly melt an ounce of pure lard over the fire, add 1/2 a teaspoonful of juice of squills, and stir up the mixture well, subsequently adding 10 drops of spirit of sal ammoniac. If the mixture is not stiff enough after cooling, the firmness may be enhanced by an admixture of 1/3 to 1/2 ounce of pure melted beef-tallow. A larger addition of tallow is necessary if the white of an egg is added. After each addition the mixture should be stirred up well and the white of egg should be added, not to the warm, but almost cold, mixture.
II. Alum, 3 parts, by weight; salt- peter, 6 parts; sulphate of zinc, 3 parts; common salt, 3 parts. Mix all into a thick paste, dip the articles into it, and heat them, until nearly black, on a piece of sheet iron over a clear coke or charcoal fire; then plunge them into cold water.
Red Gilding. This is obtained by the use of a mixture of equal parts of verdigris and powdered tartar, with which the article is coated; subsequently burning it off on a moderate coal fire. Cool in water, dip the article in a pickle of tartar, scratch it, and a handsome red shade will be the result, which has not attacked the gilding in any way.
Regilding Mat Articles. In order to regenerate dead gold trinkets without having to color them again which is, as a rule, impossible, because the gold is too weak to stand a second coloring it is advisable to copper these articles over before gilding them. After the copper has deposited all over, the object, well cleaned and scratched, is hung in the gilding. By this manipulation much time and vexation is saved, such as every jeweler will have experienced in gilding mat gold articles. The article also acquires a faultless new appearance. Here are two recipes for the preparation of copper baths:
I. Distilled boiling water, 2,000 parts, by weight; sodium sulphate, 10 parts; potassium cyanide, 15 parts; cupric acetate, 15 parts; sodium carbonate, 20 parts; ammonia, 12 parts.
II. Dissolve crystallized verdigris, 20 parts, by weight, and potassium cyanide, 42 parts, in 1,000 parts of boiling water.
Silk Gilding. This can only be accomplished by the electric process. The fiber is first rendered conductive by impregnation with silver nitrate solution and reduction of same with grape sugar and diluted alkali, or, best of all, with Raschig's reduction salt. In place of the silver nitrate, a solution of lead acetate or copper acetate may be employed. The silk thus impregnated is treated in the solution of an alkaline sulphide, e. g., sodium sulphide, ammonium sulphide, or else with hydrogen sulphide, thus producing a conductive coating of metallic sulphide. Upon this gold can be precipitated by electrodeposition in the usual way.
Spot Gilding. Gilding in spots, producing a very fine appearance, is done by putting a thin coat of oil on those parts of the metal where the gilding is not to appear; the gold will then be deposited in those spots only where there is no oil, and the oil is easily removed when the work is finished.
Gilding Steel. Pure gold is dissolved in aqua regia; the solution is allowed to evaporate until the acid in excess has gone. The precipitate is placed in clean water, 3 times the quantity of sulphuric acid is added and the whole left to stand for 24 hours in a well-closed flask, until the ethereal gold solution floats on top. By moistening polished steel with the solution a very handsome gilding is obtained. By the application of designs with any desired varnish the appearance of a mixture of gold and steel may be imparted to the article.
I. The moldings, ledges, etc., to be gilded are painted with a strong solution of joiners' glue, which is left to harden well, whereupon 8 to 10 coatings of glue mixed with whitening are given. Each coat must, of course, be thoroughly dry, before commencing the next. After this has been done, paint with a strong mixture of glue and minium, and while this is still wet, put on the gold leaflets and press them down with cotton. To impart the fine gloss, polish with a burnishing agate after the superfluous gold has been removed.
II. Proceed as above, but take silver leaf instead of gold leaf, and after all is thoroughly dry and the superfluous silver has been removed, apply a coating of good gold lacquer. The effect will be equally satisfactory.
I. Gilding by means of zinc contact may be accomplished with the following formula: Two parts, by weight, of gold chloride; 5 parts, by weight, of ootassium cyanide; 10 parts,
by weight, of sulphite of soda; and 60 parts, by weight, of sodium phosphate are dissolved in 1,000 parts of water. When used the bath must be hot. A cold bath without the addition of potassium cyanide may also be used for gilding, and this consists of 7 parts, by weight, of gold chloride; 30 parts, by weight, of yellow prussiate of potash; 30 parts, by weight, of potash; 30 parts, by weight, of common salt in 1,000 parts of water.
II. To gild zinc articles, dissolve 20 parts of gold chloride in 20 parts of distilled water, and 80 parts of potassium cyanide in 80 parts of water, mix the solutions, stir a few times, filter, and add tartar, 5 parts, and fine chalk, 100 parts. The resulting paste is applied with a brush. Objects of copper and brass are previously coated with zinc. This is done in the following manner: Heat a concentrated sal ammoniac solution to the boiling point with addition of zinc dust and immerse the thoroughly cleaned objects until a uniform zinc coating has formed. Or boil the articles in a concentrated caustic soda solution with zinc dust.
I. To plate iron and other metals with pure aluminum, deoxidize the pieces with a solution of borax and place them in an enameling oven, fitted for receiving metallic vapors. Raise the temperature to 1,882º to 2,732º F. Introduce the aluminum vapors generated by heating a quantity of the metal on the sand bath. When the vapors come in contact with the metallic surfaces, the aluminum is deposited. The vapors that have not been used or are exhausted may be conducted into a vessel of water.
To Copper Aluminum, take
Sulphate of copper 30 parts
Cream of tartar 30 parts
Soda 25 parts
Water 1,000 parts
The articles to be coppered are merely dipped in this bath, but they must be well cleaned previously.
I. By dissolving 15 parts, by weight, of tartar emetic and 15 parts of prepared tartar in 500 parts of hot water and adding 45-60 parts of hydrochloric acid and 45-60 parts of powdered antimony, brass becomes coated in the boiling liquid with beautiful antimony colors. In this manner it is possible to impart to brass, golden, copper-red, violet, or bluish-gray shades, according to a shorter or longer stay of the objects in the liquid. These antimony colors possess a handsome luster, are permanent, and never change in the air.
II. Carbonate of soda, 200 parts, by weight; sulphide of antimony, 50 parts; water, 1,000 parts. Heat the whole in a porcelain capsule for 1 hour, keeping constantly in ebullition; next, filter the solution, which, on cooling, leaves a precipitate, which boil again with the liquid for one-half hour, whereupon the bath is ready for use.
To Coat Brass Articles with Antimony Colors. Dissolve 15 parts, by weight, of tartar emetic and 15 parts, by weight, of powdered tartar in 500 parts, by weight, of hot water and add 50 parts, by weight, of hydrochloric acid, and 50 parts, by weight, of powdered antimony. Into this mixture, heated to a boil, the immersed articles become covered with luster colors, a golden shade appearing at first, which is succeeded by one of copper red. If the objects remain longer in the liquid, the color passes into violet and finally into bluish gray.
I. To brass small articles of iron or steel drop them into a quart of water and 1/2 ounce each of sulphate of copper and protochloride of tin. Stir the articles in this solution until desired color is obtained.
II. Brassing Zinc, Steel, Cast Iron, etc. Acetate of copper, 100 parts, by weight; cyanide of potassium, 250 parts; bisulphite of soda, 200 parts; liquid ammonia, 100 parts; protochloride of zinc, 80 parts; distilled water, 10,000 parts. Dissolve the cyanide of potassium and the bisulphite of soda. On the other hand, dissolve the ammonia in three fourths of the water and the protochloride of zinc in the remaining water; next, mix the two solutions. This bath is excellent for brassing zinc and is used cold.
III. Acetate of copper, 125 parts, by weight; cyanide of potassium, 400 parts; protochloride of zinc, 100 parts; liquid ammonia, 100 parts; distilled water, 8,000 to 10,000 parts. Proceed as above described.
IV. Acetate of copper, 150 parts, by weight; carbonate of soda, 1,000 parts; cyanide of potassium, 550 parts; bisulphite of soda, 200 parts; protochloride of zinc, 100 parts. Proceed as above. This bath serves for iron, cast iron, and steel, and is used cold.
Colored Rings on Metal. Dissolve 200 parts, by weight, of caustic potash in 2,000 parts of water and add 50 parts of litharge. Boil this solution for half an hour, taking care that a little of the litharge remains un dissolved. When cold, pour off the clear fluid; it is then ready for use. Move the object to and fro in the solution; a yellow-brown color appears, becoming in turn white, yellow, red, and finally a beautiful violet and blue. As soon as the desired color is obtained, remove the article quickly from the solution, rinse in clean water, and dry in sawdust.
Green or Gold Color for Brass. French articles of brass, both cast and made of sheet brass, mostly exhibit a golden color, which is produced by a copper coating. This color is prepared as follows: Dissolve 50 parts, by weight, of caustic soda and 40 parts of milk sugar in 1,000 parts of water and boil a quarter of an hour. The solution finally acquires a dark yellow color. Now add to the mixture, which is removed from the fire, 40 parts of concentrated cold blue vitriol solution. A red precipitate is obtained from the vitriol, which falls to the bottom at 167º F. Next a wooden sieve, fitted to the vessel, is put into the liquid with the polished brass articles. Toward the end of the second minute the golden color is usually dark enough. The sieve with the articles is taken out and the latter are washed and dried in sawdust. If they remain in the copper solution they soon assume a green color, which in a short time passes into yellow and bluish green, and finally into the iridescent colors. These shades must be produced slowly at a temperature of 133º to 135º F.
To Give a Green Color to Gold Jewelry. Take verdigris, 120 parts, by weight; sal ammoniac, 120 parts; ni- trate of potassium, 45 parts; sulphate of zinc, 16 parts. Grind the whole and mix with strong vinegar. Place on the fire and boil in it the articles to be colored.
Nickeling by Oxidation.
I. Nickeling may be performed on all metals cold, by means of nickelene by the Mitressey process, without employing electrical apparatus, and any desired thickness deposited. It is said to be more solid than nickel.
First Bath. Clean the objects and take 5 parts, by weight, of American potash per 25 parts, by weight, of wateI. If the pieces are quite rusted, take 2 parts, by weight, of chlorhydric acid per 1 part, by weight, of water. The bath is employed cold.
Second Bath. Put 250 parts, by weight, of sulphate of copper in 25,000 parts, by weight, of water. After dis- solution add a few drops of sulphuric acid, drop by drop, stirring the liquid with a wooden stick until it becomes as clear as spring water.
Take out the pieces thus cleaned and place them in what is called the copper bath, attaching to them leaves of zinc; they will assume a red tint. Then pass them into the nickeling bath, which is thus composed:
Cream of tartar 20 parts
Sal ammoniac, in powder 10 parts
Kitchen salt 5 parts
Oxychlorhydrate of tin 20 parts
Sulphate of nickel, single 30 parts
Sulphate of nickel, double 50 parts
Remove the pieces from the bath in a few minutes and rub them with fine sand on a moist rag. Brilliancy will thus be obtained. To improve the appearance, apply a brass wire brush. The nickeling is said to be more solid and beautiful than that obtained by the electrical method.
Brilliancy may be also imparted by means of a piece of buff glued on a wooden wheel and smeared with English red stuff. This will give a glazed appearance.
II. Prepare a bath of neutral zinc chloride and a neutral solution of a nickel salt. The objects are immersed in the bath with small pieces of zinc and kept boiling for some time. This process has given satisfactory results. It is easy to prepare the zinc chloride by dissolving it in hydrochloric acid, as well as a saturated solution of ammoniacal nickel sulphate in the proportion of two volumes of the latter to one of the zinc chloride. The objects should be boiled for 15 minutes in the bath. Nickel salt may also be employed, preferably in the state of chloride.
Pickling Solutions. Oxidized copper, brass, and German silver articles must be cleansed by acid solutions. In the case of brass alloys, this process, through which the object acquires a dull yel- low surface, is known as dipping or yellowing. The treatment consists of
several successive operations. The article is first boiled in a lye composed of 1 part caustic soda and 10 parts water, or in a solution of potash or soda or in limewater; small objects may be placed in alcohol or benzine. When all the grease has been removed, the article is well rinsed with water, and is then ready for the next pickling. It is first plunged into a mixture of 1 part sulphuric acid and 10 parts water, and allowed to remain in it till it acquires a reddish tinge. It is then immersed in 40º Bé. nitric acid, for the purpose of removing the red tinge, and then for a few seconds into a bath of 1 part nitric acid, 1.25 parts sulphuric acid of 66º Bé., 0.01 part common salt, and 0.02 parts lampblack. The article must then be immediately and carefully washed with water till no trace of acid remains. It is then ready for galvanizing or drying in bran or beech sawdust. When articles united with soft solder are pickled in nitric acid, the solder receives a gray-black color.
Palladiumizing Watch Movements. Palladium is successfully employed for coating parts of timepieces and other pieces of metals to preserve them against oxidation. To prepare a palladium bath use the following ingredients: Chloride of palladium, 10 parts, by weight; phosphate of ammonia, 100 parts; phosphate of soda, 300 parts; benzoic acid, 8 parts; water, 2,000 parts.
Metal Browning by Oxidation. The article ought first to be cleaned with either nitric acid or muriatic acid, then immersed in an acid affecting the metal and dried in a warm place. A light coating is thus formed. For a second coating acetic or formic acid is used preferably for aluminum, nickel, and copper; but for iron and steel, muriatic or nitric acid. After cleaning, the article is placed in a solution of tannin or gallic acid, and is then dried in a warm place as before. The second coating is of a yellowish-brown color. On placing it near the fire, the color can be deepened until it becomes completely black; care must be taken to withdraw it when the desired shade is produced. Instead of the acids employed for the first coating, ammonia may be used.
Silvering by Oxidation. The oxidizing of silver darkens it, and gives an antique appearance that is highly prized.
I. The salts of silver are colorless when the acids, the elements of which enter into their composition, are not colored, but they generally blacken on exposure to light. It is easy, therefore, to blacken silver and obtain its oxide; it is sufficient to place it in contact with a sulphide, vapor of sulphur, sulphohydric acids, such as the sulphides or polysulphides of potash, soda, dissolved in water and called eau de barége. The chlorides play the same part, and the chloride of lime in solution or simply Javelle water may be used. It is used hot in order to accelerate its action. The bath must be prepared new for each operation for two reasons: (1) It is of little value; (2) the sulphides precipitate rapidly and give best effects only at the time of their direct precipitations. The quantity of the reagent in solution, forming the bath, depends upon the thickness of the deposit of silver. When this is trifling, the oxidation penetrates the entire deposit and the silver exfoliates in smaller scales, leaving the copper bare. It is necessary, therefore, in this case to operate with dilute baths inclosing only about 45 grains of oxidizant at most per quart. The operation is simple: Heat the necessary quantity of water, add the sulphide or chloride and agitate to effect the solution of the mixture, and then at once plunge in the silver-plated articles, leaving them immersed only for a few seconds, which exposure is sufficient to cover it with a pellicle of deep black-blue silver. After withdrawing they are plunged in clean cold water, rinsed and dried, and either left mat or else polished, according to the nature of the articles.
Should the result not be satisfactory, the articles are brightened by immersing them in a lukewarm solution of cyanide of potassium. The oxide, the true name of which would be the sulphuret or chloruret, can be raised only on an object either entirely of silver or silver plated.
II. Rub the article with a mixture of graphite, 6 parts, and powdered bloodstone, 1 part, moistened with oil of turpentine. Allow to dry and brush with soft brushes passed over wax. Or else, brush with a soft brush wet with alcoholic or aqueous platinic chloride solution of 1 in 20.
III. Sulphurizing is effected with the following methods: Dip in a solution heated to about 175º F., of potassium sulphide, 5 parts, by weight; ammonium carbonate, 10 parts; water, 1,000 parts; or, calcium sulphide, 1 to 2 parts; sal ammoniac, 4 parts; water, 1.000 parts.
IV. In the following solution articles of silver obtain a warm brown tone: Copper sulphate, 20 parts, by weight; potassium nitrate, 10 parts; ammonium chloride, 20 parts. By means of bromine, silver and silver alloys receive a black coloring. On engraved surfaces a niello-like effect may be produced thereby.
I. Mix together bismuth chloride, 1 part; mercury bichloride, 2 parts; copper chloride, 1 part; hydrochloric acid, 6 parts; alcohol, 5 parts; and water, 5 parts. To use this mixture successfully the articles to be oxidized must be cleaned perfectly and freed from all grease, which is best accomplished by boiling them in a soda solution or by washing in spirit of wine. Care should be taken not to touch the article with the fingers again after this cleaning. However clean the hand may be, it always has grease on it and leaves spots after touching, especially on steel. Next the object is dipped into the liquid, or if this is not possible the solution is applied thin but evenly with a brush, pencil, or rabbit's foot. When the liquid has dried, the article is placed for a half hour in simple boiling water. If a very dark shade is desired the process is repeated until the required color is attained.
II. Apply, by means of a sponge, a solution of crystallized iron chloride, 2 parts; solid butter of antimony, 2 parts; and gallic acid, 1 part in 5 parts of water. Dry the article in the air and repeat the treatment until the desired shade is reached. Finally rinse with water, dry, and rub with linseed-oil varnish.
Tinning by Oxidation. A dipping bath for tinning iron is prepared by dissolving 300 parts, by weight, ammonia alum (sulphate of alumina and sulphate of ammonia) and 10 parts of melted stannous chloride (tin salt) in 20,000 parts of warm water. As soon as the solution boils, the iron articles, previously pickled and rinsed in fresh water, are plunged into the fluid; they are immediately covered with a layer of tin of a beautiful dull-white color, which can be made bright by treatment in a tub or sack. Small quantities of tin salt are added from time to time as may be required to replace the tin deposited on the iron. This bath is also well adapted for tinning zinc, but here also, as with iron, the deposit is not sufficient to prevent oxidation of the metal below. Larger articles tinned in this way are polished by scratch brushing. In tinning zinc by this process, the ammonia alum may be replaced by any other kind of alum, or aluminum sulphate may be used alone; experience has shown, however, that this cannot be done with iron, cast iron, or steel. If it is desired to tin other metals besides iron and zinc in the solution which we have described, the battery must be resorted to; if the latter is used, the above solution should be applied in preference to any other.
PATINA OXIDIZING PROCESSES:
Patina of Art Bronzes. For all patinas, whether the ordinary brown of commerce, the green of the Barye bronzes, or the dark-orange tint of the Florentine bronzes, a brush is used with pigments varying according to the shade desired and applied to the metal after it is warmed. Recipes are to be met with on every hand that have not been patented. But the details of the operation are the important thing, and often the effect is produced by a handicraft which it is difficult to penetrate.
I. A dark tint may be obtained by cleaning the object and applying a coat of hydrosulphate of ammonia; then, after drying it, by rubbing with a brush smeared with red chalk and plumbago. The copper may also be moistened with a dilute solution of chloride of platina and warmed slightly, or still by plunging it in a warm solution of the hydrochlorate of antimony. For the verde antique a solution is recommended com- posed of 200 grams of acetic acid of 8º strength, the same quantity of common vinegar, 30 parts, by weight, of carbonate of ammonia; 10 parts, by weight, of sea salt; with the same quantities of cream of tartar and acetate of copper and a little water. To obtain the bronze of medals several processes afford a selection: For example, the piece may be dipped in a bath consisting of equal parts of the perchloride and the sesquiazotate of iron, warming to the evaporation of the liquid, and rubbing with a waxed brush.
II. Dissolve copper nitrate, 10 parts, by weight, and kitchen salt, 2 parts, in 500 parts of water and add a solution of ammonium acetate obtained by neutralization of 10 parts of officinal spirit of sal ammoniac with acetic acid to a faintly acid reaction, and filling up with water to 500 parts. Immerse the bronze, allow to dry, brush off superficially and repeat this until the desired shade of color has been obtained.
A Permanent Patina for Copper.
Sodium chloride 37 parts
Ammonia water 75 parts
Ammonium chloride 37 parts
Strong wine vinegar 5,000 parts
Mix and dissolve. Apply to object to be treated, with a camel's hair pencil. Repeat the operation until the desired shade of green is reached.
Oxalic acid 5 parts
Ammonium chloride 10 parts
Acetic acid, 30 per cent dilution 500 parts
Mix and dissolve. Use as above indicated. The following will produce the same result:
Potassium oxalate, acid 4 parts
Ammonium chloride 16-17 parts
Vinegar containing 6 per cent
of acetic acid 1,000 parts
IV. Bluish Green. After using the first formula (for green) pencil over with the following solution:
Ammonium chloride 40 parts
Ammonium carbonate 120 parts
Water 1,000 parts
Mix and dissolve.
Potassium su1phuret 5 parts
Water 1,000 parts
Mix and dissolve. With this, pencil over object to be treated, let dry, then pencil over with 10 parts a mixture of a saturated solution of ammonia water and acetic acid and 5 parts of ammonium chloride thinned with 1,000 parts of water. Let dry again, then brush off well. Repeat, if necessary, until the desired hue is attained.
Another Blue Green.
Corrosive sublimate 25 parts
Potassium nitrate 86 parts
Borax 56 parts
Zinc oxide 113 parts
Copper acetate 220-225 parts
Mix and heat together on the surface of the object under treatment.
VII. Brown. The following is a Parisian method of producing a beautiful deep brown:
Potassium oxalate, acid 3 parts
Ammonium chloride 15 parts
Water, distilled 280 parts
Mix and dissolve. The object is penciled over with this several times, each time allowing the solution to dry before putting on any more. The process is slow, but makes an elegant finish.
Green Patina Upon Copper. To produce a green patina upon copper take tartaric acid, dilute it half and half with boiling water; coat the copper with this; allow to dry for one day and rub the applied layer off again the next day with oakum. The coating must be done in dry weather, else no success will be obtained. Take hydrochloric acid and dilute it half and half with boiling water, but the hydrochloric acid should be poured in the water, not vice-versa, which is dangerous. In this hydrochloric acid water dissolve as much zinc as it can solve and allow to settle. The clear liquid is again diluted half with boiling water and the copper is coated with this a few times.
Black Patina. Black patina is obtained by coating with tallow the pieces to be oxidized and lighting with a rosin torch. Finally, wipe the reliefs and let dry.
Blue-Black Patina. Use a dilute solution of chloride of antimony in water and add a little free hydrochloric acid. Apply with a soft brush, allow the article to dry and rub with a flannel. If expense is no object, employ a solution of chloride of palladium, which gives a magnificent blue black. It is necessary, however, to previously clean the articles thoroughly in a hot solution of carbon- ate of soda, in order to remove the dirt and greasy matter, which would prevent the patina from becoming fixed.
Red Patina. The following is a new method of making a red patina, the so-called blood bronze, on copper and copper alloys. The metallic object is first made red hot, whereby it becomes covered with a coating consisting of cupric oxide on the surface and cuprous oxide beneath. After cooling, it is worked upon with a polishing plate until the black cupric oxide coating is removed and the cuprous oxide appears. The metal now shows an intense red color,
with a considerable degree of luster, both of which are so permanent that it can be treated with chemicals, such as blue vitriol, for instance, without being in the least affected.
If it is desired to produce a marbled surface, instead of an even red color, borax or some chemical having a similar action is sprinkled upon the metal during the process of heating. On the places covered by the borax, oxidation is pre- vented, and after polishing, spots of the original metallic color will appear in the red surface. These can be colored by well-known processes, so as to give the desired marbled appearance.
Platinizing Aluminum. Aluminum vessels coated with a layer of platinum are recommended in place of platinum vessels, when not exposed to very high temperatures. The process of platinizing is simple, consisting in rubbing the aluminum surface, previously polished, with platinic chloride, rendered slightly alkaline. The layer of platinum is made thicker by repeated application. Potash lye is carefully added to a solution of 5 to 10 per cent of platinic chloride in water till a slightly alkaline reaction is produced on filtering paper or a porcelain plate by means of phenolphthalein. This solution must always be freshly prepared, and is the best for the purpose. Neither galvanizing nor amalgamating will produce the desired result. Special care must be taken that the aluminum is free from iron, otherwise black patches will arise which cannot be removed. Vessels platinized in this way must not be cleaned with substances such as sea sand, but with a 5 to 10 per cent solution of oxalic acid in water, followed by thorough rinsing in water. These vessles are said to be specially suitable for evaporating purposes.
Platinizing Copper and Brass.
I. The articles are coated with a thin layer of platinum in a boiling solution of platinum sal ammoniac, 1 part; sal ammoniac, 8 parts; and water, 40 parts, and next polished with chalk. A mixture of equal parts of platinum sal ammoniac and tartar may also be rubbed on the objects. Steel and iron articles can be platinized with an ethereal solution of platinic chloride. For small jewelry the boiling solution of platinic chloride, 10 parts; cooking salt, 200 parts; and water, 1,000 parts, is employed, which is rendered alkaline with soda lye. In this, one may also work with zinc contact.
II. Heat 800 parts of sal ammoniac and 10 parts of platinum sal ammoniac to the boiling point with 400 parts of water, in a porcelain dish, and place the articles to be platinized into this, whereby they soon become covered with a coating of platinum. They are then removed from the liquid, dried and polished with whiting.
Platinizing on Glass or Porcelain. First dissolve the platinum at a moderate temperature in aqua regia, and next evaporate the solution to dryness, observing the following rules: When the solution commences to turn thick it is necessary to diminish the fire, while carrying the evaporation so far that the salt becomes dry, but the solution should not be allowed to acquire a brown color, which occurs if the heat is too strong. The result of this first operation is chloride of platina. When the latter has cooled off it should be dissolved in alcohol (95 per cent). The dissolution accomplished, which takes place at the end of 1 or 2 hours, throw the solution gradually into four times its weight of essence of lavender, then put into a well- closed flask.
For use, dip a brush into the solution and apply it upon the objects to be platinized, let dry and place in the muffle, leaving them in the oven for about one half hour. In this operation one should be guided as regards the duration of the baking by the hardness or fusibility of the objects treated. The platinization accomplished, take a cotton cloth, dipped into whiting in the state of pulp, and rub the platinated articles with this, rinsing with water afterwards.
Platinizing Metals. Following are several processes of platinizing on metals:
It is understood that the metals to be covered with platinum must be copper or coppered. All these baths require strong batteries.
I. Take borate of potash, 300 parts, by weight; chloride of platina, 12 parts; distilled water, 1,000 parts.
II. Carbonate of soda, 250 parts, by weight; chloride of platina, 10 parts; distilled water, 1,000 parts.
III. Sulphocyanide of potash, 12 parts, by weight; chloride of platina, 12 parts; carbonate of soda, 12 parts; distilled water, 1,000 parts.
IV. Borate of soda, 500 parts, by weight; chloride of platina, 12 parts; distilled water, 1,000 parts.
SILVERING, SILVER-PLATING, AND DESILVERING:
See also Silvering by Oxidation, under Oxidation Processes, under Plating.
Antique Silver. There are various processes for producing antique silver, either fat or oxidized:
To a little copal varnish add some finely powdered ivory black or graphite. Thin with spirits of turpentine and rub with a brush dipped into this varnish the objects to be treated. Allow to dry for an hour and wipe off the top of the articles with some rag, so that the black remains only in the hollows. If a softer tint is desired, apply again with a dry brush and wipe as the first time. The coating of black will be weaker and the shade handsomer.
I. The article should first be cleaned and then rubbed by means of a wet cloth with a pinch of powder obtained by mixing together: Nitrate of silver, 1 part; cyanide of potassium, 2 parts; chalk, 5 parts. Then wipe with a dry cloth, and polish well with rouge to give brilliancy.
II. By the electric method the metal is simply plunged into a hot saturated solution of crude potassium carbonate, and the plating is then done directly, using a strong electrical current. The potassium carbonate solution dissolves the surface of the britannia metal and thus enables the silver to take a strong hold on the article.
To Silver Brass, Bronze, Copper, etc.
I. In order to silver copper, brass, bronze, or coppered metallic articles, dissolve 10 parts of lunar caustic in 500 parts of distilled water, and 35 parts of potassium cyanide (98 per cent) in 500 parts of distilled water; mix both solutions with stirring, heat to 176º to 194º F. in an enameled vessel, and enter the articles, well cleansed of fat and impurities, until a uniform coating has formed.
II. Zinc, brass, and copper are silvered by applying a paste of the following composition: Ten parts of silver nitrate dissolved in 50 parts of distilled water, and 25 parts of potassium cyanide dissolved m distilled water; mix, stir, and filter. Moisten 100 parts of whiting and 400 parts of powdered tartar with enough of the above solution to make a paste-like mass, which is applied by means of a brush on the well-cleaned objects. After the drying of this coating, rinse off, and dry in sawdust.
III. To silver brass and copper by friction, rub on the articles, previously cleaned of grease, a paste of silver chloride, 10 parts; cooking salt, 20 parts; powdered tartar, 20 parts; and the necessary water, using a rag.
I. It often happens in plating that, notwithstanding all precautions, some pieces have failed and it is necessary to commence the work again. For removing the silver that has been applied, a rapid method is to take sulphuric acid, 100 parts, and nitrate of potash, 10 parts. Put the sulphuric acid and the nitrate of potash (saltpeter) in a vessel of stoneware or porcelain, heated on the water bath. When the silver has been removed from the copper, rinse the object several times and recommence the silvering. This bath may be used repeatedly, taking care each time to put it in a stoppered bottle. When it has been saturated with silver and has no more strength, decant the deposit, boil the liquor to dryness, add the residue to the deposit, and melt in a crucible to regenerate the metal.
II. To dissolve the silver covering of a metallic object, a bath is made use of, composed of 66 per cent sulphuric acid, 3 parts, and 40 per cent nitric acid, 1 part. This mixture is heated to about 176º F., and the objects to be desilvered are suspended in it by means of a copper wire. The operation is accomplished in a few seconds. The objects are washed and then dried in sawdust.
To Silver Glass Balls and Plate Glass. The following is a method for silvering the glass balls which are used as ornaments in gardens, glass panes, and concave mirrors: Dissolve 300 parts of nitrate of silver and 200 parts of ammonia in 1,300 parts of distilled water. Add 35 parts of tartaric acid dissolved in 4 times its weight of water. Dilute the whole with 15,000 to 17,000 parts of distilled water. Prepare a second solution containing twice the amount of tartaric acid as the preceding one. Apply each of these solutions successively for 15 to 20 minutes on the glass to be silvered, which must previously have been cleaned and dried. When the silvering is sufficient, wash the object with hot water, let dry, and cover with a brown varnish.
I. Iron articles are plated with quicksilver in a solution of nitrate of mercury before being silvered. The quicksilver is then removed by heating to 572º F. The articles may also be first tinned to economize the silver. Steel is dipped in a mixture of
nitrate of silver and mercury, each dissolved separately in the proportion of 5 parts, by weight, to 300 parts, by weight, of water, then wiped to remove the black film of carbon, and silvered till a sample dipped in a solution of blue vitriol ceases to turn red. According to H. Krupp, articles made of an alloy of nickel, copper, and zinc, such as knives, forks, spoons, etc., should be coated electrically with nickel, put into a solution of copper like that used for galvanic coppering, and then electroplated.
II. A brilliant silver color may be imparted to iron (from which all grease has been previously removed) by treating it with the following solution: Forty parts, by weight, chloride of antimony; 10 parts, by weight, powdered arsenious acid; and 80 parts levigated hematite are mixed with 1,000 parts of 90 per cent alcohol and gently heated for half an hour on a water bath. A partial solution takes place, and a small cotton pad is then dipped in the liquid and applied with a gentle pressure to the iron. A thin film consisting of arsenic and antimony is precipitated, as described by Dr. Langbein, in his "Handbuch der galv. Metallniederschläge." The brilliancy of the effect depends upon the care with which the iron has previously been polished.
To Silver-Plate Metals.
I. Nitrate of silver, 30 parts, by weight; caustic potash, 30 parts; distilled water, 100 parts. Put the nitrate of silver into the water; one quarter hour afterwards add the potash, and, when the solution is done, filter. It is sufficient to dip the objects to be silvered into this bath, moving them about in it for 1 or 2 minutes at most; then rinsing and drying in sawdust. It is necessary to pickle the pieces before using the bath. To make the nitrate of silver one's self, take 30 parts of pure silver and 60 parts of nitric acid, and when the metal is dissolved add the caustic potash and the water.
II. Kayser's silvering liquid, which is excellent for all kinds of metals, is prepared from lunar caustic, 11 parts; sodium hyposulphite, 20 parts; sal ammoniac, 12 parts; whiting, 20 parts; and distilled water, 200 parts. The articles must be cleaned well.
Mosaic Silver. This compound consists of tin, 3 parts, by weight; bismuth, 3 parts; and mercury, 1 1/2 parts. The alloy of these metals is powdered finely, thus forming a silvery mass used for imitation silvering of metals, paper, wood, etc. In order to impart to metals, especially articles of copper and brass, an appearance similar to silver, they are made perfectly bright. The powder of the mosaic silver is mixed with six times the volume of bone ashes, adding enough water to cause a paste and rubbing this on the metallic surface by means of a cork of suitable shape. In order to silver paper by means of this preparation it is ground with white of egg, diluted mucilage, or varnish, and treated like a paint.
Pastes for Silvering.
I. Carbonate of lime, 65 parts; sea salt, 60 parts; cream of tartar, 35 parts; nitrate of silver, 20 parts. Bray all in a mortar, not adding the carbonate of lime until the other substances are reduced to a fine powder. Next, add a little water to form a homogeneous paste, which is preserved in blue bottles away from the fight. For use, put a little of this paste on a small pad and rub the article with it.
II. Articles of zinc, brass, or copper may also be silver plated by applying to them a pasty mass of the following composition: First dissolve 10 parts, by weight, of nitrate of silver in 50 parts, by weight, of distilled water; also 25 parts, by weight, of potassium cyanide in sufficient distilled water to dissolve it. Pour the two together, stir well, and filter. Now 100 parts, by weight, of whiting or levigated chalk and 400 parts, by weight, of potassium bitartrate, finely powdered, are moistened with the above solution sufficiently to form a soft paste, which may be applied to the objects, previously well cleansed, with a brush. After this coating has dried well, rinse it off, and dry the object in clean sawdust.
I. Take 100 parts, by weight, of distilled water and divide it into two equal portions. In the one dissolve 10 parts of silver nitrate and in the other 25 parts of potassium cyanide. The two solutions are reunited in a single vessel as soon as completed. Next prepare a mixture of 100 parts of Spanish white, passed through a fine sieve, 10 parts of cream of tartar, pulverized, and 1 part of mercury. This powder is stirred in a portion of the above liquid so as to form a rather thick paste. The composition is applied by means of the finger, covered with a rag, on the object to be silvered. The application must be as even as possible. Let the object dry .and wash in pure water. The excess of powder is removed with a brush.
II. The following is a process used when the jeweler has to repair certain pieces from which silvering has come off
in places, and which he would like to repair without having recourse to the battery, and specially without having to take out the stones or pearls: Take nitrate of silver, 25 parts, by weight; cyanide of potassium, 50 parts; cream of tartar, 20 parts; Paris white, 200 parts; distilled water, 200 parts; mercury, 2 parts. Dissolve the nitrate of silver in half of the distilled water and the cyanide in the other half; mix the two liquids; next bray well in a mortar the mercury, Paris white, and cream of tartar. Preserve the products of these two operations separately, and when you wish to use them make a rather soft paste of the two, which apply with a little cotton or a brush on the portion to be silvered. Let dry and subsequently rub with a soft brush.
Tin Silver-Plating. Prepare a solution of 3 parts, by weight, of bismuth subnitrate in 10 parts of nitric acid of 1.4 specific gravity, to which add a solution of 10 parts of tartar and 40 parts of hydrochloric acid in 1,000 parts of water. In the mixture of these solutions immerse the tin articles freed from grease and oxide. The pulverous bismuth precipitated on the surface is rubbed off, whereupon the objects appear dark steel gray. For silvering prepare a mixture of 10 parts of silver chloride; 30 parts of cooking salt; 20 parts of tartar, and 100 parts of powdered chalk, which is rubbed in a slightly moist state on the bismuth surface of the tin articles, using a flannel rag. The silver separates only in a very thin layer, and must be protected against power and light before tarnishing by a coating of preservative or celluloid varnish.
Zinc Contact Silver-Plating. According to Buchner, 10 parts, by weight, of silver nitrate is dissolved in water and precipitated by the addition of hydrochloric acid in the form of silver chloride, which is washed several times in clean water; now dissolve 70 parts, by weight, of spirit of sal ammoniac in water, and add to it 40 parts, by weight, of soda crystals, 40 parts, by weight, of pure potassium cyanide, and 15 parts, by weight, of common salt. Now thin down the compound with sufficient distilled water to make a total of 1,000 parts.
Tin Plating of Lead. Lead plates are best tinned by plating. For this purpose a table with a perfectly even iron surface and provided with vertical raised edges to prevent the melted metal from flowing away, is employed. The lead is poured on this table, and covered with grease to prevent oxidation of the surface. As soon as the lead is congealed, melted tin is poured over it, care being taken that the tin is sufficiently heated to remelt the surface of the lead and combine thoroughly with it. When the plate is sufficiently cooled, it is turned over, and the lower surface treated in the same way. The plate, thus tinned on both sides, is then placed between rollers, and can be rolled into very thin sheets without injury to the tin coating. These sheets, doubly coated with tin by this process, are specially adapted for lining cases intended for the transport of biscuits, chocolate, candies, tea, snuff, etc. If lead plates are only to be tinned superficially, they are heated to a tolerably high temperature, and sprinkled with powdered rosin; melted tin is then rubbed on the surface of the plate with a ball of tow. It is advisable to give the lead a fairly thick coating of tin, as the latter is rendered thinner by the subsequent rolling.
To Ascertain whether an Article is Nickeled, Tinned, or Silvered. When necessary to ascertain quickly and accurately the nature of the white metal covering an object, the following process will be found to give excellent results:
Nickeled Surface. If the article has a nickel coating, a drop of hydrochloric acid, deposited on a spot clean and free from grease, will quickly develop a green- ish tint. If the object is kept for 5 or 10 minutes in a solution composed of 60 parts of sea salt and 110 parts of water, it will receive a very characteristic reddish tint. A drop of sulphuret of sodium does not change a nickeled surface.
Tinned Surface. A tinned object may be recognized readily by applying hydrochloric acid, which, even diluted, will remove the tin. The salt solution, used as previously described, produces a gray tint, faint in certain cases. The sulphuret of sodium dissolves tin.
Silvered Surface. In the case of a silvered article a drop of nitric acid will remove the silver, while hydrochloric acid will scarcely attack it. The salt solution will produce no effect. The sulphuret of sodium will blacken it rapidly.
PLATINUM PAPERS - POLISHES
PLATINUM PAPERS AND THEIR DEVELOPMENT:
See Photography, under Developing Papers.
PLATINUM WASTE, TO SEPARATE SILVER FROM:
To Make Plush Adhere to Metal. Wash off with ordinary soda water the bottom of a tin box, wiping it dry with cloth. Coat the tin with the juice of onion and press on this space a piece of strong paper, smoothing it out so that there will be no blisters. When this has dried, the paper will adhere, so that it can be removed only by scraping with a sharp instrument. Then give a coat of hot glue to the paper and press the plush down into the glue, and when dry and hard, the plush can be removed only by placing the tin box in boiling water.
PLUSH, TO REMOVE GREASE SPOTS FROM:
See Cleaning Preparations and Methods.
POISONS, ANTIDOTES FOR:
Polishes for Aluminum. I. M. Mouray recommends the use of an emulsion of equal parts of rum and olive oil, made by shaking these liquids together in a bottle. When a burnishing stone is used, the peculiar black streaks first appearing should not cause vexation, since they do not injure the metal in the least, and may be removed with a woolen rag. The object in question may also be brightened in potash lye, in which case, however, care must be taken not to have the lye too strong. For cleaning purposes benzol has been found best.
II. Aluminum is susceptible of taking a beautiful polish, but it is not white like that of silver or nickel, rather slightly bluish, like tin. The shade can be improved. First, the grease is to be removed from the object with pumice stone. Then, for polishing, use is made of an emery paste mingled with tallow, forming cakes which are rubbed on the polishing brushes. Finally, rouge powder is employed with oil of turpentine.
Polishes for Bars, Counters, etc.
Linseed oil 8 ounces
Stale ale 8 ounces
Hydrochloric acid 1 ounce
Alcohol, 95 per cent 1 ounce
White of 1 egg
Mix. Shake before using. Clean out the dust, dirt, etc., using an appropriate brush, or a bit of cloth wrapped around a stick, then apply the above, with a soft brush, or a bit of cotton wrapped in a bit of silk or, in fact, any convenient method, of applying it.
Japan wax 1 av. ounce
Oil of turpentine 3 fluidounces
Linseed oil 16 fluidounces
Alcohol 3 fluidounces
Solution of potash 1 1/2 fluidounces
Water to make 32 fluidounces.
Dissolve the wax in the turpentine, add the other ingredients, diluting the potash solution with the water before adding to the other ingredients, and stir briskly until well mixed.
POLISHES FOR BRASS, BRONZE, COPPER, ETC.
Objects of polished copper, bronze, brass, and other alloys of copper tarnish through water and it is sometimes necessary to give them again their bright appearance. Pickle the articles in an acid bath; wash them next in a neutral bath; dry them, and subsequently rub them with a polishing powder. Such is the general formula; the processes indicated below are but variants adapted to divers cases and recommended by disinterested experimenters:
Sharp Polishes. The following three may be used on dirty brasses, copper articles, etc., where scratching is not objectionable:
Quartz sand, powdered
and levigated 20 parts
Paris red 30 parts
Vaseline 50 parts
Mix intimately and make a pomade.
Emery flour, finest levigated 50 parts
Paris red 50 parts
Mutton suet 40 parts
Oleic acid 40 parts
Levigated emery powder 100 parts
Anhydrous sodium carbonate 5 parts
Tallow soap 20 parts
Water 100 parts
Copper Articles. Make a mixture of powdered charcoal, very fine, 4 parts; spirit of wine, 3 parts; and essence of turpentine, 2 parts. To this add water in which one third of its weight of sorrel salt or oxalic acid has been stirred, and rub the objects with this mixture.
Bronze Articles. Boil the objects in soap lye, wash in plenty of water, and dry in sawdust.
Highly Oxidized Bronzes. First dip in strong soda lye, then in a bath containing 1 part of sulphuric acid to 12 parts of water. Rinse in clean water, and next in water containing a little ammonia. Dry and rub with a polishing powder or paste.
POLISHES FOR FLOORS.
I. Throw a handful of permanganate potash crystals into a pail of boiling water, and apply the mixture as hot as possible to the floor with a large flat brush. If the stain produced is not dark enough, apply one or two more coats as desired, leaving each wash to dry thoroughly before applying another. If it is desired to polish the surface with beeswax, a coat of size should be applied to the boards before staining, as this gives depth and richness to the color. After 3 or 4 days, polish well with a mixture of turpentine and beeswax. A few cents will cover the cost of both size and permanganate of potash.
Potash 1 part
Water 4 parts
Yellow beeswax 5 parts
Hot water, a sufficient quantity.
Emulsify the wax by boiling it in the water in which the potash has been dissolved; stir the whole time. The exact amount of boiling is determined by the absence of any free water in the mass. Then remove the vessel from the fire, and gently pour in a little boiling water, and stir the mixture carefully. If a fat like mass appears without traces of watery particles, one may know the mass is in a fit condition to be liquefied by the addition of more hot water without the water separating. Then put in the water to the extent of 200 to 225 parts, and reheat the compound for 5 to 10 minutes, without allowing it to reach the boiling point. Stir constantly until the mixture is cool, so as to prevent the separation of the wax, when a cream like mass results which gives a quick and brilliant polish on woodwork, if applied in the usual way, on a piece of flannel rag, and polished by rubbing with another piece of flannel.
Colored Floor Polishes.
Yellow: Caustic soda solution, 7 1/2 parts, mixed with 1 1/2 to 2 parts of finely powdered ocher, heated with 2 1/2 parts of yellow wax, and stirred until uniformly mixed. A reddish-brown color may be obtained by adding 2 parts of powdered umber to the above mixture.
I. Natural umber, 1/2 part; burnt umber, 1 part; and yellow ocher, 1 part, gives a fine red-brown color when incorporated with the same wax and soda mixture.
II. Treat 5 pounds of wax with 15 pounds of caustic soda lye of 3º Bé. so that a uniform wax milk results; boil with pound of annatto, 3 pounds of yellow ocher, and 2 pounds of burnt umber.
Mahogany Brown. Boil 5 pounds of wax with 15 pounds of caustic soda lye as above. Then add 7 pounds of burnt umber very finely powdered, making it into a uniform mass by boiling again.
Yellow ocher. The wax milk obtained as above is boiled with 5 pounds of yellow ocher.
The mass on cooling has the consistency of a salve. If it is to be used for rubbing the floor it is stirred with sufficient boiling water so as to form a fluid of the consistency of thin syrup or oil. This is applied very thin on the floor, using a brush; then it is allowed to dry only half way, and is rubbed with a stiff floor brush. The polishing is continued with a woolen rag until a mirror like gloss is obtained. It is best not to paint the whole room and then brush, but the deals should be taken one after the other, otherwise the coating would become too dry and give too dull a luster. The floors thus treated with gloss paste are very beautiful. To keep them in this condition they should be once in a while rubbed with a woolen rag, and if necessary the color has to be renewed in places. If there are parquet floors whose patterns are not to be covered up, the ocher (yellow) paste or, better still, the pure wax milk is used.
French Polish. The wood to be polished must be made perfectly smooth and all irregularities removed from the surface with glass paper; next oil the work with linseed oil, taking care to rub off all superfluous oil. (If the wood is white no oil should be used, as it imparts a slight color.) Then prepare a wad or rubber of wadding, taking care there are no hard lumps in it. After the rubber is prepared pour on it a small quantity of polish. Then cover it with a piece of old cotton rag (new will
not answer). Put a small drop of oil with the finger on the surface of the rubber, and then proceed to polish, moving the rubber in lines, making a kind of figure of eight over the work. Be very careful that the rubber is not allowed to stick or the work will be spoilt. A little linseed oil facilitates the process. When the rubber requires more polish, turn back the rag cover, pour on the polish, replace the cover, oil and work as before. After this rubbing has proceeded for a little time and the whole surface has been gone over, the work must be allowed to stand for a few hours to harden, and then be rubbed down smooth with very fine emery paper. Then give another coat of polish. If not smooth enough, emery paper again. This process must continue until the grain is filled up. Finish off with a clean rubber with only spirit on it (no polish), when a clear bright surface should be the result. Great care must be taken not to put the polish on too freely, or you will get a rough surface. After a little practice all difficulties will vanish. The best French polish will be found to be one made only from good pale orange shellac and spirit, using 3 pounds of shellac for each gallon of spirit. The latter should be of 63 to 64º over-proof. A weak spirit is not suitable and does not make a good polish. A few drops of pure linseed oil make the polish work more freely.
POLISHES FOR FURNITURE.
First make a paste to fill cracks as follows: Whiting, plaster of Paris, pumice stone, litharge, equal parts; japan dryer, boiled linseed oil, turpentine, coloring matter of sufficient quantity. Rub the solids intimately with a mixture of 1 part of the japan, 2 parts of the linseed oil, and 3 parts of turpentine, coloring to suit with Vandyke brown or sienna. Lay the filling on with a brush, let it set for about 20 minutes, and then rub off clean except where it is to remain. In 2 or 3 days it will be hard enough to polish.
After the surface has been thus prepared, the application of a coat of first class copal varnish is in order. It is recommended that the varnish be applied in a moderately warm room, as it is injured by becoming chilled in drying. To get the best results in varnishing, some skill and experience are required. The varnish must be kept in an evenly warm temperature, and put on neither too plentifully nor too gingerly.
After a satisfactorily smooth and regular surface has been obtained, the polishing proper may be done. This may be accomplished by manual labor and dexterity, or consist in the application of a very thin, even coat of a very fine, transparent varnish.
If the hand-polishing method be preferred, it may be pursued by rubbing briskly and thoroughly with the following finishing polish:
Alcohol 8 ounces
Shellac 2 drachms
Gum benzoin 2 drachms
Best poppy oil 2 drachms
Dissolve the shellac and gum in the alcohol in a warm place, with frequent agitation, and, when cold, add the poppy oil. This may be applied on the end of a cylindrical rubber made by tightly rolling a piece of flannel which has been torn, not cut, into strips 4 to 6 inches wide.
A certain "oily sweating" of articles of polished wood occurs which has been ascribed to the oil used in polishing, but has been found to be due to a waxy substance present in shellac, which is often used in polishing. During the operation of polishing, this wax enters into close combination with the oil, forming a soft, greasy mass, which prevents the varnish from ever becoming really hard. This greasy matter exudes in the course of time. The remedy is to use only shellac from which the vegetable wax has been completely removed. This is accomplished by making a strong solution of the shellac in alcohol and then shaking it up with fresh seed lac or filtering it through seed lac. In this way the readily soluble rosins in the seed lac are dissolved, and with them traces of coloring matter. At the same time the vegetable wax, which is only slightly soluble, is deposited. The shellac solution which has exchanged its vegetable wax for rosin is not yet suitable for fine furniture polishing. It is not sufficiently taken up by the wood, and an essential oil must be added to give it the necessary properties, one of the best oils to employ for this purpose being that of rosemary. The following recipe is given:
II. Twenty pounds of shellac and 4 pounds of benzoin are dissolved in the smallest possible quantity of alcohol, to- gether with 1 pound of rosemary oil. The solution then obtained is filtered through seed lac so as to remove whatever vegetable wax may be present.
Red Furniture Paste.
Soft water 6 pints
Turpentine 6 pints
Beeswax 3 pounds
White wax 1 1/2 ounces
White soap 18 ounces
Red lead 12 ounces
Cut up soap and dissolve in water by aid of heat; then evaporate to 6 pounds. Melt the waxes and add turpentine in which red lead has been stirred, pour into this the soap solution, and stir until it is nearly cold. If a darker color is wanted add more red lead, 4 to 6 ounces.
Beechwood Furniture. The wood of the red beech is known to acquire, by the use of ordinary shellac polish, a dirty yellow color, and by the use of white polish, prepared from bleached shellac, an unsightly gray-white color. There- fore, where light colors are desired, only filtered shellac polish should be employed, and in order to impart some fire to the naturally dull color of the beech- wood the admixture of a solution of dragon's blood in alcohol for a red shade, or turmeric in alcohol for yellow may be used. A compound of the red and yellow liquids gives a good orange shade. A few trials will soon show how much coloring matter may be added to the polish.
Polishes for Glass.
I. Mix calcined magnesia with purified benzine to a semi-liquid paste. Rub the glass with this mixture by means of a cotton wad, until it is bright.
II. Crush to powder cologne chalk, 60 parts, by weight; tripoli, 30 parts, by weight; bole, 15 parts, by weight. For use moisten the glass a little, dip a linen rag into the powder and rub the glass until it is clean.
III. Tin ashes may be employed with advantage. The glass is rubbed with this substance and then washed off with a piece of soft felt. In this manner a very handsome polish is obtained.
Polishes for Ivory, Bone, etc.
I. First rub with a piece of linen soaked with a paste made of Armenian bole and oleic acid. Wash with Marseilles soap, dry, rub with a chamois skin, and finally render it bright with an old piece of silk. If the ivory is scratched, it may be smoothed by means of English red stuff on a cloth, or even with a piece of glass if the scratches are rather deep, n the hollow parts of ivory objects the paste can be made to penetrate by means of an old toothbrush.
II. Tortoise-shell articles have a way of getting dull and dingy looking. To re-polish dip the finger in linseed oil and rub over the whole surface. Very little oil should be used, and if the article is a patterned one it may be necessary to use a soft brush to get it into the crevices. Then rub with the palm of the hand until all oil has disappeared, and the shell feels hot and looks bright and shiny.
Marble Polishing. Polishing includes five operations. Smoothing the roughness left on the surface is done by rubbing the marble with a piece of moist sandstone; for moldings either wooden or iron mullers are used, crushed, and wet sandstone, or sand, more or less fine, according to the degree of polish required, being thrown under them. The second process is continued rubbing with pieces of pottery without enamel, which have only been baked once, also wet. If a brilliant polish is required, Gothland stone instead of pottery is used, and potter's clay or fuller's earth is placed beneath the muller. This operation is performed upon granites and porphyry with emery and a lead muller, the upper part of which is incrusted with the mixture until reduced by friction to clay or impalpable powder. As the polish depends almost entirely upon these two operations, care must be taken that they are performed with a regular and steady movement. When the marble has received the first polish, the flaws, cavities, and soft spots are sought out and filled with mastic of a suitable color.
This mastic is usually composed of a mixture of yellow wax, rosin, and Burgundy pitch, mixed with a little sulphur and plaster passed through a fine sieve, which gives it the consistency of a thick paste; to color this paste to a tone analogous to the ground tints or natural cement of the material upon which it is placed, lampblack and rouge, with a little of the prevailing color of the material, are added. For green and red marbles, this mastic is sometimes made of gum lac, mixed with Spanish sealing wax of the color of the marble. It is applied with pincers, and these parts are polished with the rest. Sometimes crushed fragments of marble are introduced into the cement, but for fine marbles the same colors are employed which are used in painting, and which will produce the same tone as the ground; the gum lac is added to give it body and brilliancy.
The third operation in polishing consists in rubbing it again with a hard pumice stone, under which water is being constantly poured, unmixed with sand. For the fourth process, called
softening the ground, lead filings are mixed with the emery mud produced by the polishing of mirrors or the working of precious stones, and the marble is rubbed by a compact linen cushion well saturated with this mixture; rouge is also used for this polish. For some outside works, and for hearths and paving tiles, marble workers confine themselves to this polish. When the marbles have holes or grains, a lead muller is substituted for the linen cushion. In order to give a perfect brilliancy to the polish, the gloss is applied. Wash well the prepared surfaces and leave them until perfectly dry, then take a linen cushion, moistened only with water, and a little powder of calcined tin of the first quality. After rubbing with this for some time take another cushion of dry rags, rub with it lightly, brush away any foreign substance which might scratch the marble, and a perfect polish will be obtained. A little alum mixed with the water used penetrates the pores of the marble, and gives it a speedier polish. This polish spots very easily and is soon tarnished and destroyed by dampness. It is necessary when purchasing articles of polished marbles to subject them to the test of water; if there is too much alum, the marble absorbs the water and a whitish spot is left.
Polishing powders are advantageously prepared according to the following recipes:
I. Four pounds magnesium carbonate, 4 pounds chalk, and 4 pounds rouge are intimately mixed.
II. Four pounds magnesium carbonate are mixed with 1/4 pound fine rouge.
III. Five pounds fine levigated whiting and 2 pounds Venetian red are ground together.
Kieselguhr 42 pounds
Putty powder 14 pounds
Pipe clay 14 pounds
Tartaric acid 1 1/2 pounds
Powder the acid, mix well with the others. This is styled "free from mercury, poisonous mineral acids, alkalies, or grit." It may be tinted with 12 ounces of oxide of iron if desired.
Malt vinegar 4 gallons
Lemon juice 1 gallon
Paraffine oil 1 gallon
Kieselguhr 7 pounds
Powdered bath brick 3 pounds
Oil lemon 2 ounces
Kieselguhr 56 pounds
Paraffine oil 3 gallons
Methylated spirit 1 1/2 gallons
Camphorated spirit 1/2 gallon
Turpentine oil 1/2 gallon
Liquid ammonia fort 3 pints
Rotten stone 16 av. ounces
Paraffine 8 av. ounces
Kerosene (coal oil) 16 fluidounces
Oil of mirbane enough to perfume.
Melt the paraffine, incorporate the rotten stone, add the kerosene, and the oil of mirbane when cold.
Oxalic acid 1/2 av. ounce
Rotten stone 10 av. ounces
Kerosene (coal oil) 30 fluidounces
Paraffine 2 av. ounces
Pulverize the oxalic acid and mix it with rotten stone; melt the paraffine, add to it the kerosene, and incorporate the powder; when cool, add oil of mirbane or lavender to perfume.
Pour the ammonia into the oil, methylated spirits, and turpentine, add the camphorated spirit and mix with the kieselguhr. To prevent setting, keep well agitated during filling. The color may be turned red by using a little sesquioxide of iron and less kieselguhr. Apply with a cloth, and when dry use another clean cloth or a brush.
Powdered pipe clay 112 pounds
Tallow soap 16 pounds
Tartaric acid 1 1/4 pounds
Grind until pasty, afterwards press into blocks by the machine.
Levigated flint 60 pounds
Whiting 52 pounds
Tallow 20 pounds
Caustic soda 5 pounds
Water 2 gallons
Dissolve the soda in water and add to the tallow; when saponified, stir in the others, pressing as before.
Saponified cocoanut oil 56 pounds
Kieselguhr 12 pounds
Alum 5 1/2 pounds
Flake white 5 1/2 pounds
Tartaric acid 3/4 pounds
Make as before.
Tallow soap 98 pounds
Liquid glycerine soap 14 pounds
Whiting 18 pounds
Levigated flint 14 pounds
Powdered pipe clay 14 pounds
White petroleum jelly 90 pounds
Kieselguhr 30 pounds
Refined paraffine wax 10 pounds
Refined chalk or whiting 10 pounds
Sodium hyposulphite 8 pounds
Melt wax and jelly, stir in others and grind.
It is an undecided point as to whether a scented paste is better than one without perfume. The latter is added merely to hide the nasty smell of some of the greases used, and it is not very nice to have spoons, etc., smelling, even tasting, of mirbane, so perhaps citronelle is best for this purpose. It is likely to be more pure. The dose of scent is usually at the rate of 4 ounces to the hundredweight.
Dehydrated soda 5 parts
Curd soap 20 parts
Emery flour 100 parts
To be stirred together on a water bath with water, 100 parts, until soft.
Turpentine 1 part
Emery flour 1 part
Paris red 2 parts
Vaseline 2 parts
Mix well and perfume.
Stearine 8 to 9 parts
Mutton suet 32 to 38 parts
Stearine oil 2 to 2.5 parts
Melt together and mix with Vienna chalk, in fine powder, 48 to 60 parts; Paris red, 20 parts.
Rotten stone 1 part
Iron subcarbonate 3 parts
Lard oil, a sufficient quantity.
Iron oxide 10 parts
Pumice stone 32 parts
Oleic acid, a sufficient quantity.
Soap, cut fine 16 parts
Precipitated chalk 2 parts
Jewelers' rouge 1 part
Cream of tartar 1 part
Magnesium carbonate 1 part
Water, a sufficient quantity.
Dissolve the soap in the smallest quantity of water over a water bath. Add the other ingredients to the solution while still hot, stirring all the time to make sure of complete homogeneity. Pour the mass into a box with shallow sides, and afterwards cut into cubes.
Non-Explosive Liquid Metal Polish. Although in a liquid form, it does not necessarily follow that a liquid polish is less economical than pastes, because the efficiency of both is dependent upon the amount of stearic or oleic acid they contain, and a liquid such as that given be- low is as rich in this respect as most of the pastes, especially those containing much mineral jelly and earthy matters which are practically inert, and can only be considered as filling material. Thus it is a fact that an ounce of fluid polish may possess more polishing potency than an equal weight of the paste. Proportions are: Sixteen pounds crude oleic acid; 4 pounds tasteless mineral oil; 5 pounds kieselguhr; 1 1/2 ounces lemon oil. Make the earthy matter into a paste with the mixed fluids and gradually thin out, avoiding lumps. Apply with one rag, and finish with another.
Miscellaneous Metal Polishes.
I. Articles of polished copper, such as clocks, stove ornaments, etc., become tarnished very quickly. To restore their-brilliancy dip a brush in strong vinegar and brush the objects to be cleaned. Next pass through water and dry in sawdust. A soap water, in which some carbonate of soda has been dissolved, will do the same service.
II. This is recommended for machinery by the chemical laboratory of the industrial museum of Batavia:
Oil of turpentine 15 parts
Oil of stearine 25 parts
Jewelers' red 25 parts
of superior quality 45 parts
Alcohol is added to that mixture in such a quantity as to render it almost liquid, then by means of a brush it is put on those parts that are to be polished. When the alcohol has dried, the remaining cover is rubbed with a mixture of 45 parts of animal charcoal and 25 parts jewelers' red. The rubbed parts will become quite clean and bright.
III. The ugly spots which frequently show themselves on nickel-plated objects may be easily removed with a mixture of 1 part sulphuric acid and 50 parts alcohol. Coat the spots with this solution, wipe off after a few seconds, rinse off thoroughly with clean water, and rub dry with sawdust.
IV. Crocus, dried and powdered, when applied with chamois leather to nickel-plated goods, will restore their brilliancy without injuring their surface.
V. Articles of tin should be ground
and polished with Vienna lime or Spanish white. The former may be spread on linen rags, the latter on wash leather. Good results may be obtained by a mixture of about equal parts of Vienna lime, chalk, and tripolI. It should be moistened with alcohol, and applied with a brush. Subsequent rubbing with roe skin (chamois) will produce a first-rate polish. Tin being a soft metal, the above polishing substances may be very fine.
VI. To polish watch cases, take two glasses with large openings, preferably two preserving jars with ground glass covers. Into one of the glass vessels pour 1 part of spirit of sal ammoniac and 3 parts water, adding a little ordinary barrel soap and stirring everything well. Fill the other glass one half with alcohol. Now lay the case to be cleaned, with springs and all, into the first-named liquid and allow to remain therein for about 10 to 20 seconds. After protracted use this time may be extended to several minutes. Now remove the case, quickly brush it with water and soap and lay for a moment into the alcohol in the second vessel. After drying off with a clean cloth heat over a soldering flame for quick drying and the case will now look almost as clean and neat as a new one. The only thing that may occur is that a polished metal dome may become tarnished, but this will only happen if either the mixture is too strong or the case remains in it too long, both of which can be easily avoided with a little practice. Shake before using.
VII. This is a cleanser as well as polisher:
Prepared chalk 2 parts
Water of ammonia 2 parts
Water sufficient to make 8 parts
The ammonia saponifies the grease usually present.
It must be pointed out that the alkali present makes this preparation somewhat undesirable to handle, as it will affect the skin if allowed too free contact.
The density of the liquid might be increased by the addition of soap; the solid would, of course, then remain longer in suspension.
VIII . Serviettes Magiques. These fabrics for polishing articles of metal consist of pure wool saturated with soap and tripoli, and dyed with a little coralline. They are produced by dissolving 4 parts of Marseilles soap in 20 parts of water, adding 2 parts of tripoli and saturating a piece of cloth 3 inches long and 4 inches wide with it, allowing to dry.
IX. In order to easily produce a mat polish on small steel articles use fine powdered oil stone, ground with turpentine.
Polishes for Pianos.
Alcohol, 95 per cent 300 parts
Benzol 700 parts
Gum benzoin 8 parts
Sandarac 16 parts
Mix and dissolve. Use as French polish.
Beeswax 2,500 parts
Potassium carbonate 25 parts
Oil of turpentine 4,000 parts
Water, rain or distilled 4,500 parts
Dissolve the potassium carbonate in 1,500 parts of the water and in the solution boil the wax, shaved up, until the latter is partially saponified, replacing the water as it is driven off by evaporation. When this occurs remove from the fire and stir until cold. Now add the turpentine little by little, and under constant agitation, stirring until a smooth, homogeneous emulsion is formed. When this occurs add the remainder of the water under constant stirring. If a color is wanted use alkanet root, letting it macerate in the oil of turpentine be- fore using the latter (about an ounce to the quart is sufficient). This preparation is said to be one of the best polishes known. The directions are very simple: First wash the surface to be polished, rinse, and dry. Apply the paste as evenly and thinly as possible over a portion of the surface, then rub off well with a soft woolen cloth.
Polishes for Silverware. The best polish for silverware that is, the polish that, while it cleans, does not too rapidly abrade the surface is levigated chalk, either alone or with some vegetable acid, like tartaric, or with alum. The usual metal polishes, such as tripoli (diatomaceous earth), finely ground pumice stone, etc., cut away the surface so rapidly that a few cleanings wear through ordinary plating.
White lead 5 parts
Chalk, levigated 20 parts
Magnesium carbonate 2 parts
Aluminum oxide 5 parts
Silica 3 parts
Jewelers' rouge 2 parts
Each of the ingredients must be reduced to an impalpable powder, mixed carefully, and sifted through silk several
times to secure a perfect mixture, and to avoid any possibility of leaving in the powder anything that might scratch the silver or gold surface. This may be left in the powder form, or incorporated with soap, made into a paste with glycerine, or other similar material. The objection to mixtures with vaseline or greasy substances is that after cleaning the object must be scrubbed with soap and water, while with glycerine simple rinsing and running water instantly cleans the object. The following is also a good formula:
Chalk, levigated 2 parts
Oil of turpentine 4 parts
Stronger ammonia water 4 parts
Water 10 parts
Mix the ammonia and oil of turpentine by agitation, and rub up the chalk in the mixture. Finally rub in the water gradually or mix by agitation. Three parts each of powdered tartaric acid and chalk with 1 part of powdered alum make a cheap and quick silver cleaning powder.
III. Mix 2 parts of beechwood ashes with 4/100 of a part of Venetian soap and 2 parts of common salt in 8 parts of rain water. Brush the silver with this, using a pretty stiff brush. A solution of crystallized permanganate of potash is often recommended, or even the spirits of hartshorn, for removing the grayish violet film which forms upon the surface of the silver. Finally, when there are well determined blemishes upon the surface of the silver, they may be soaked 4 hours in soapmakers' lye, then cover them with finely powdered gypsum which has been previously moistened with vinegar, drying well before a fire; now rub them with something to remove the powder. Finally, they are to be rubbed again with very dry bran.
POLISHES FOR STEEL AND IRON.
The polishing of steel must always be preceded by a thorough smoothing, either with oilstone dust, fine emery, or coarse rouge. If any lines are left to be erased by means of fine rouge, the operation becomes tedious and is rarely successful. The oilstone dust is applied on an iron or copper polisher. When it is desired to preserve the angles sharp, at a shoulder, for instance, the polisher should be of steel. When using diamantine an iron polisher, drawn out and flattened with a hammer, answers very well. With fine rouge, a bronze or bell metal polisher is preferable for shoulders; and for flat surfaces, discs or large zinc or tin polishers, although glass is preferable to either of these. After each operation with oilstone dust, coarse rouge, etc., the polisher, cork, etc., must be changed, and the object should be cleaned well, preferably by soaping, perfect cleanliness being essential to success. Fine rouge or diamantine should be made into a thick paste with oil; a little is then taken on the polisher or glass and worked until quite dry. As the object is thus not smeared over, a black polish is more readily obtained, and the process gets on better if the surface be cleaned from time to time.
For Fine Steel. Take equal parts (by weight) of ferrous sulphate green vitriol and sodium chloride cooking salt mix both well together by grinding in a mortar and subject the mixture to red heat in a mortar or a dish. Strong fumes will develop, and the mass begin to flow. When no more fumes arise, the vessel is removed from the fire and allowed to cool. A brown substance is obtained with shimmering scales, resembling mica. The mass is now treated with water, partly in order to remove the soluble salt, partly in order to wash out the lighter portions of the non-crystallized oxide, which yield an excellent polishing powder. The fire must be neither too strong nor too long continued, otherwise the powder turns black and very hard, losing its good qualities. The more distinct the violet-brown color, the better is the powder.
For polishing and cleaning fenders, fire irons, horses' bits, and similar articles: Fifty-six pounds Bridgewater stone; 28 pounds flour emery; 20 pounds rotten stone; 8 pounds whiting. Grind and mix well.
To make iron take a bright polish like steel, pulverize and dissolve in 1 quart of hot water, 1 ounce of blue vitriol; 1 ounce of borax; 1 ounce of prussiate of potash; 1 ounce of charcoal; 1/2 pint of salt, all of which is to be added to one gallon of linseed oil and thoroughly mixed. To apply, bring the iron or steel to the proper heat and cool in the solution.
Stove Polish. The following makes an excellent graphite polish:
Ceresine 12 parts
Japan wax 10 parts
Turpentine oil 100 parts
Lampblack, best 12 parts
Graphite, levigated 10 parts
Melt the ceresine and wax together, remove from the fire, and when half
cooled off add and stir in the graphite and lampblack, previously mixed with the turpentine.
Ceresine 23 parts
Carnauba wax 5 parts
Turpentine oil 220 parts
Lampblack 300 parts
Graphite, finest levigated 25 parts
Mix as above.
III. Make a mixture of water glass and lampblack of about the consistency of thin syrup, and another of finely levigated plumbago and mucilage of Soudan gum (or other cheap substitute for gum arabic), of a similar consistency. After getting rid of dust, etc., go over the stove with mixture No. I and let it dry on, which it will do in about 24 hours. Now go over the stove with the second mixture, a portion of the surface at a time, and as this dries, with an old blacking brush give it a polish. If carefully done the stove will have a polish resembling closely that of new Russian iron. A variant of this formula is as follows: Mix the graphite with the water glass to a smooth paste; add, for each pound of paste, 1 ounce of glycerine and a few grains of aniline black. Apply to the stove with a stiff brush.
POLISHES FOR WOOD:
See also Polishes for Furniture, Floors and Pianos.
In the usual method of French polishing, the pad must be applied along curved lines, and with very slight pressure, if the result is to be uniform. To do this requires much practice and the work is necessarily slow. Another disadvantage is that the oil is apt to sweat out afterwards, necessitating further treatment. According to a German patent all difficulty can be avoided by placing between the rubber and its covering a powder composed of clay or loam, or better, the powder obtained by grinding fragments of terra cotta or of yellow pricks. The powder is moistened with oil for use. The rubber will then give a fine polish, without any special delicacy of manipulation and with mere backward and forward rubbing in straight lines, and the oil will not sweat out subsequently. Another advantage is that no priming is wanted, as the powder fills up the pores. The presence of the powder also makes the polish adhere more firmly to the wood.
Oak Wood Polish. The wood is first carefully smoothed, then painted with the following rather thickly liquid mass, using a brush, viz.: Mix 1 1/2 parts, by weight, of finely washed chalk (whiting), 1/2 part of dryer, and 1 part of boiled linseed oil with benzine and tint (umber with a little lampblack, burnt sienna). After the applied mixture has become dry, rub it down, polish with glass powder, and once more coat with the same mixture. After this filling and after rubbing off with stickwood chips or fine sea grass, one or two coats of shellac are put on (white shellac with wood alcohol for oak, brown shellac for cherry and walnut). This coating is cut down with sandpaper and given a coat of varnish, either polishing varnish, which is polished off with the ball of the hand or a soft brush, or with interior varnish, which is rubbed down with oil and pumice stone. This polish is glass hard, transparent, of finer luster, and resistive.
Hard Wood Polish. In finishing hard wood with a wax polish the wood is first coated with a "filler," which is omitted in the case of soft wood. The filler is made from some hard substance, very finely ground; sand is used by some manufactures.
The polish is the same as for soft wood. The simplest method of applying wax is by a heated iron, scraping off the surplus, and then rubbing with a cloth. It is evident that this method is especially laborious; and for that reason solution of the wax is desirable. It may be dissolved rather freely in turpentine spirit, and is said to be soluble also in kerosene oil.
The following recipes give varnish-like polishes:
I. Dissolve 15 parts of shellac and 15 parts of sandarac in 180 parts of spirit of wine. Of this liquid put some on a ball of cloth waste and cover with white linen moistened with raw linseed oil. The wood to be polished is rubbed with this by the well-known circular motion. When the wood has absorbed sufficient polish, a little spirit of wine is added to the polish, and the rubbing is continued. The polished articles are said to sustain no damage by water, nor show spots or cracks.
II. Orange shellac, 3 parts; sandarac, 1 part; dissolved in 30 parts of alcohol. For mahogany add a little dragon's blood.
III. Fifteen parts of oil of turpentine, dyed with anchusine, or undyed, and 4 parts of scraped yellow wax are stirred into a uniform mass by heating on the water bath.
IV. Melt 1 part of white wax on the water bath, and add 8 parts of petroleum. The mixture is applied hot. The petroleum evaporates and leaves behind a thin layer of wax, which is subsequently rubbed out lightly with a dry cloth rag.
Stearine 100 parts
Yellow wax 25 parts
Caustic potash 60 parts
Yellow laundry soap 10 parts
Water, a sufficient quantity.
Heat together until a homogeneous mixture is formed.
Yellow wax 25 parts
Yellow laundry soap 6 parts
Glue 12 parts
Soda ash 25 parts
Water, a sufficient quantity.
Dissolve the soda in 400 parts of water, add the wax, and boil down to 250 parts, then add the soap. Dissolve the glue in 100 parts of hot water, and mix the whole with the saponified wax.
VII. This is waterproof. Put into a stoppered bottle 1 pint alcohol; 2 ounces gum benzoin; 1/4 ounce gum sandarac, and 1/4 ounce gum anime. Put the bottle in a sand bath or in hot water till the solids are dissolved, then strain the solution, and add 1/4 gill best clear poppy oil. Shake well and the polish is ready for use.
VIII. A white polish for wood is made as follows:
White lac 1 1/2 pounds
Powdered borax 1 ounce
Alcohol 3 pints
The lac should be thoroughly dried, especially if it has been kept under water, and, in any case, after being crushed, it should be left in a warm place for a few hours, in order to remove every trace of moisture. The crushed lac and borax are then added to the spirit, and the mixture is stirred frequently until solution is effected, after which the polish should be strained through muslin.
IX. To restore the gloss of polished wood which has sweated, prepare a mixture of 100 parts of linseed oil, 750 parts of ether, 1,000 parts of rectified oil of turpentine, and 1,000 parts of petroleum benzine, perfumed, if desired, with a strongly odorous essential oil, and colored, if required, with cuicuma, orlean, or alkanna. The objects to be treated are rubbed thoroughly with this mixture, using a woolen rag.
MISCELLANEOUS POLISHING AGENTS:
Polishing Agent which may also be used for Gilding and Silvering. The following mediums hitherto known as possessing the aforenamed properties, lose these qualities upon having been kept for some time, as the metal salt is partly reduced. Furthermore, it has not been possible to admix reducing substances such as zinc to these former polishing agents, since moisture causes the metal to precipitate. The present invention obviates these evils. The silver or gold salt is mixed with chalk, for instance, in a dry form. To this mixture, fine dry powders of one or more salts (e.g., ammonia compounds) in whose solutions the metal salt can enter are added; if required, a reducing body, such as zinc, may be added at the same time. The composition is pressed firmly together and forms briquettes, in which condition the mass keeps well. For use, all that is necessary is to scrape off a little of the substance and to prepare it with water.
Silver Polishing Balls. This polishing agent is a powder made into balls by means of a binding medium and enjoys much popularity in Germany. It is prepared by adding 5 parts of levigated chalk to 2 parts of yellow tripoli, mixing the two powders well and making into a stiff paste with very weak gum water - 1 part gum arabic to 12 parts of water. This dough is finally shaped by hand into balls of the size of a pigeon's egg. The balls are put aside to dry on boards in a moderately warm room, and when completely hard are wrapped in tin-foil paper.
To Prepare Polishing Cloths. The stuff must be pure woolen, colored with aniline red, and then put in the following:
Castile soap, white 4 parts
Jewelers' red 2 parts
Water 20 parts
Mix. One ounce of this mixture will answer for a cloth 12 inches square, where several of them are saturated at the same time. For the workshop, a bit of chamois skin of the same size (a foot square), is preferable to wool, on account of its durability. After impregnation with the soap solution, it should be dried in the air, being manipulated while drying to preserve its softness and suppleness.
To Polish Delicate Objects. Rub the objects with a sponge charged with a mixture of 28 parts of alcohol, 14 parts of water, and 4 parts of lavender oil.
Polish for Gilt Frames. Mix and beat the whites of 3 eggs with one-third, by weight, of javelle water, and apply to the gilt work.
Steel Dust as a Polishing Agent. Steel dust is well adapted for polishing precious stones and can replace emery with advantage. It is obtained by spraying water on a bar of steel brought to a high temperature. The metal becomes friable and can be readily reduced to powder in a mortar. This powder is distinguished from emery by its mordanting properties and its lower price. Besides, it produces a finer, and consequently, a more durable polish.
Polishing Bricks. Stir into a thick pulp with water 10 parts of finely powdered and washed chalk, 1 part of English red, and 2 parts of powdered gypsum; give it a square shape and dry.
Denaturized alcohol 400 parts
Spirit of sal ammoniac 75 parts
Water 150 parts
Petroleum ether 80 parts
Infusorial earth 100 parts
Red bole or white bole 50 parts
Calcium carbonate 100 parts
Add as much of the powders as desired. Mirbane oil may be used for scenting.
Infusorial earth (Kieselguhr) 8 ounces
Paraffine 2 ounces
Lubricating oil 6 fluidounces
Oleic acid 1 fluidounce
Oil mirbane 30 minims
Melt the paraffine with the lubricating oil, and mix with the infusorial earth, then add the oleic acid and oil of mirbane.
To Polish Paintings on Wood. According to the statements of able cabinet makers who frequently had occasion to cover decorations on wood, especially aquarelle painting, with a polish, a good coating of fine white varnish is the first necessity, dammar varnish being employed for this purpose. This coat is primarily necessary as a protective layer so as to preserve the painted work from destructive attacks during the rubbing for the production of a smooth surface and the subsequent polishing. At all events, the purest white polishing varnish must be used for the polish so as to prevent a perceptible subsequent darkening of the white painting colors. Naturally the success here is also dependent upon the skill of the polisher. To polish painting executed on wood it is necessary to choose a white, dense, fine grained wood, which must present a well-smoothed surface before the painting. After the painting the surface is faintly coated with a fine, quickly drying, limpid varnish. When the coating has dried well, it is carefully rubbed down with finely pulverized pumice stone, with tallow or white lard, and now this surface is polished in the usual manner with a good solution prepared from the best white shellac.
Polishing Mediums. For iron and steel, stannic oxide or Vienna lime or iron oxide and sometimes steel powder is employed. In using the burnisher, first oil is taken, then soap water, and next Vienna lime.
For copper, brass, German silver, and tombac, stearine oil and Vienna lime are used. Articles of brass can be polished, after the pickling, in the lathe with employment of a polish consisting of shellap, dissolved in alcohol, 1,000 parts; powdered turmeric, 1,000 parts; tartar, 2,000 parts; ox gall, 50 parts; water, 3,000 parts.
Gold is polished with ferric oxide (red stuff), which, moistened with alcohol, is applied to leather.
For polishing silver, the burnisher or bloodstone is employed, using soap water, thin beer, or a decoction of soap wort. Silver-plated articles are also polished with Vienna lime.
To produce a dull luster on gold and silver ware, glass brushes, i.e, scratch brushes of finely spun glass threads, are made use of.
Pewter articles are polished with Vienna lime or whiting; the former on a linen rag, the latter on leather.
If embossed articles are to be polished, use the burnisher, and for polish, soap water, soap wort decoction, ox gall with water.
Antimony-lead alloys are polished with burnt magnesia on soft leather or with fine jewelers' red.
Zinc is brightened with Vienna lime or powdered charcoal.
Vienna lime gives a light -colored polish on brass, while ferric oxide imparts a dark luster.
Rouge or Paris Red. This appears in commerce in many shades, varying from brick red to chocolate brown. The color, however, is in no wise indicative of its purity or good quality, but it can be accepted as a criterion by which to de-